Structure elucidation studies have been successfully conducted on the alkaloids from the venoms of four South American Megalomyrmex ant species. This work resulted in the development of a novel micro-degradative approach for determining the stereochemistry of 3,5-dialkylpyrrolizidine alkaloids. Synthesis of these compounds confirmed the assignments of the compounds in the ants and in the South American amphibians, where they occur as defensive neurotoxins. In addition, a set of novel unsaturated pyrrolines was discovered in the course of this work. Behavioral and morphological evidence and their structures suggest that these compounds function by inactivating AO and ALDH enzymes. FTIR spectroscopy has been used to assign the .structures of a series of dimethylalkylpyrazines. A pyrroline phosponate intermediate in the preparation of some of the above venom alkaloids has been found to possess remarkable magnetic resonance properties. A series of nine synthetic venom alkaloids has been submitted to the NCI for anti-AIDS and anti-cancer screening and to the U.S. Army Medical Research Institute of Infectious Diseases for antiviral screening. A series of amino acid-lipids has been prepared to probe peptide and protein membrane interaction. Preliminary studies have shed light on charge-charge interactions between proteins and membranes and even between charges within protein molecules.